Hepatitis B
Blood-borne viral hepatitis caused by HBV; can present as acute icteric hepatitis or evolve into chronic infection with cirrhosis and hepatocellular carcinoma risk. UK management includes antiviral suppression for chronic disease and neonatal vaccination programmes.
Key Facts
Key points
- Serology: HBsAg, anti-HBc (IgM in acute), anti-HBs after vaccination; HBeAg reflects replication in some cases.
- Chronic HBV (HBsAg >6 months): assess HBV DNA, ALT, fibrosis (elastography/biomarkers).
- First-line antivirals: tenofovir alafenamide 25 mg OD, tenofovir disoproxil 245 mg OD, or entecavir 500 mcg–1 mg OD (adjust renal impairment).
- Pegylated interferon rarely used in selected cases — specialist.
- Vaccination: Engerix B/HBVaxPRO schedules for infants, healthcare workers, risk groups.
Overview
Transmission
Parenteral, sexual, perinatal. Vaccination and antenatal HBsAg screening reduce vertical transmission.
Natural history
Acute infection may be anicteric; chronic infection risk is inversely related to age at acquisition.
Clinical Presentation
Acute
Malaise, jaundice, RUQ pain, arthralgia, urticaria (immune complex).
Chronic
Often asymptomatic until cirrhosis complications — screen at-risk migrants.
Differential Diagnosis
| Condition | Serology pattern |
|---|---|
| Hepatitis A | Anti-HAV IgM positive |
| Hepatitis C | Anti-HCV, HCV RNA |
| Autoimmune hepatitis | Autoantibodies, IgG |
| Drug-induced liver injury | Drug history |
Diagnosis / Investigation
Blood tests
LFTs, HBsAg, HBV DNA, HIV, HCV co-infection screen, AFP surveillance if cirrhosis.
Imaging
USS HCC surveillance if advanced fibrosis.
Management
Acute
Supportive care; tenofovir if severe acute HBV (specialist).
Chronic — treat if significant fibrosis or high DNA/ALT (criteria per EASL/NICE specialist pathways)
- Entecavir 500 mcg OD (treatment-naïve) — check renal adjustment.
- Tenofovir disoproxil 245 mg OD with renal monitoring.
Prevention
- HBV vaccine for contacts; HBIG for needlestick exposure per protocol.
Prognosis
Suppression reduces fibrosis progression; HCC risk persists — surveillance continues.
Other Relevant Information
Pregnancy
Tenofovir may be used in third trimester if high viral load to reduce transmission — specialist.